This invention relates to a liquid metal ion source and in particular to a liquid metal ion source provided with a function to form a pulsed ion beam, suitable for ameliorating working speed and controllability in fabrication and for increasing analyzing sensitivity in analysis, when it is applied to microfabrication or microanalysis for the fabrication of semiconductor devices.
In a prior art liquid metal ion source, as described in Japanese Patent Unexamined Publication No. 58-32346, a DC voltage has been applied between the ion emitter tip and the extracting electrode as the ion extracting voltage and a DC ion beam has been utilized. That is, heretofore, with a liquid metal ion source no pulsed ion beam has been utilized. The difficulty to form a pulsed ion beam has been due to the fact that it is difficult to obtain pulsed voltage having a voltage of several kV as well as good rising and falling characteristics.